randall



(NoYModel.) 2 Sheets--Sheet 1.

C. A. RANDALL.

' tlELlaPlolqY.

No. 554,141. `Patented Feb/4, 1896.

lJNTTnD STATES PATENT Ori-Ton.

CHARLES ADAMS RANDALL, OF LONDON, ENGLAND.

TELEPHONY.

SPECIFICATION forming part of Letters Patent No. 554,141, dated February4, 1896. Application filed December 31, 1894. Serial No. 533,449. (Nomodel.)

T0 aZZ whom, t may concern:

Be it known that I, CHARLES ADAMS RAN- DALL, a citizen of the UnitedStates, residing at London, England, have invented new and usefulImprovements in Telephony and Apparatus Connected Therewith, of whichthe following is a specification.

Provisional patents for Great Britain were applied for in March, 1894,Nos. 4,554 and 4, 572, and complete applications filed December 3,1894;also patents applied for in France and Belgium in September, 1894, forFrance, No. 228,167; Belgium, No. 85,383.

This invention relates to a novel plan or method for utilizing through atelephonie transmitting apparatus an electric current from a battery orbatteries or other source of electric power, whereby an electric currentadapted to the work to be done, such as the reliabletransinission ofarticulate speech over long circuits, cables, and the like, can be util`ized without sparking or other detrimental effects, the invention alsorelating to new and improved apparatus adapted thereto and to use intelephony generally.

In the drawings accompanying this speciication, Figure 1 represen ts aplan view of the lower or bottom side of a telephonie transmittingapparatus with the circuit-connections therefrom to the batteries,induction-coils, and main-line circuit. Fig. 2 represents thetransmitter in normal position, showing part side and sectional viewsand side view of an induction-coil and its support. Fig. 3 representsmodified arrangements of Fig. 2, also` partly in section. Fig. 4represents a modified form of construction, support, arrangement, andadjustment of electrodes shown partly in section. view of modified formof construction and arrangement of electrodes and other parts of theapparatus.

Like Iigures and letters represent corresponding parts.

In the drawings, the numeral 1 represents a frame, base or part of a boxor case for containing the devices, to which the ring2 is secured byscrews 3 3', and also the induction coil or coils 4, as at 5. The ring 2is provided with a threaded recess 6, into which the annularclamping-piece 10 is adjustably fitted. The lower part of the ring 2forms a seat 7,

Fig. 5 represents sectional' that supports an` annular washer, of feltor similar material 8, upon which rests the diaphragm 9, preferably ofcarbon,the diaphragm being held in place and with proper tension bymeans of the clamping-piece 10 when adj usted into correct position uponthe diaphragm or an annular pad or washer thereon.

1 A supporting-piece, of vulcanite or other non-conduotin g material 11,is secured adj ustably, by means of suitable soft-rubber pieces 2 andscrews 13 13, to the ring 2. The piece 11 is provided with one or moreopenings 14 to 14', eight openings being shown in this case, through orin which the electrodes pass or are contained that contact directly orotherwise with the diaphragm.

In Fig. 2 two sections of the transmitter 14 144, taken on the line oczo, Fig. 1, are shown, in which the electrodes 15 15 are attached tosuitable flat springs 16 and secured to 11 by screws 17, said springsbeing adjustable by means of adjusting-screws 1S passing therethroughinto the piece 11. The electrodes 15 15, shown partly in section, arepreferably of carbon and concave or hollow at their upper ends, andsurrounded by a tubular piece of felt or rubber 19 and an annular washeror pad, of cotton-wadding or other soft material 20, that bears upon thediaphragm with suitable pressure, such washer serving to act as adampener upon the diaphragm and also to keep in place the granulatedcarbon or other suitable granular pieces of conducting material 21,interposed between the diaphragm 9 and the electrode 15, the propernominal contact of the conducting parts or electrodes 15 21 9 beingobtained by the adjustment of the spring 16 by the screw 18. A suitablemouthpiece 22, shown broken oft, is provided and secured to the frame 1.

In Fig. 3 certain modifications are shown and the position of the partsreversed. In this form of construction the supportingpiece 11 isadjustably arranged, similarly as in Fig. 2, but above the diaphragm '9,the mouthpiece 22 being below the same. The diaphragm, as shown, restsupon a suitable annular washer 8 in the recess or seat in the ring 2,and is held in place by two or more` spring-lingers 23, secured to ring2 by screws 24, although any other convenient means may be employed.

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The electrode 26, of metal or carbon, tubular in form, is attached to aspring 16, secured together with the metal piece 27 to the support 11 bythe screw 2S. A suitable soft washer 2O is provided, preferably securedto 11, and arranged to surround the electrode 26, and to rest or bearwith suitable pressure upon the diaphragm 9, the pressure being obtainedby the adjustment and position of 11. Interposed between 9 and theelectrode 26, and partly and loosely contained within the electrode, isa small quantity of granulated carbon or other suitable material 21, theproper contact between the granulated material lying between thediaphragm and the end surface of the electrode 26 being obtained by theadjustment of the spring 16 by the screw 18 in the piece 27, thematerial contained within the electrode loosely, and resting upon thediaphragm, forming at the same time a microphonic contact between theparts 9 and 26, which are thus maintained continuously in light normalcontact, whereby the rupturin g of the circuit, sparking, and harshnoises or imperfect articulation are prevented and the conducting andvarying of the total current of the battery, or thereabout, ispractically obtained. A inodicat-ion of this form of construction isshown in Fig. 3, section 14', in which the electrode 29 is supportedupon a spring 16, the screws 30 30, which pass through the spring intothe support 11, serving to carry 29 toward the diaphragm 9, whichmovement is limited bythe screws 31 31in the pieces 32 32 on the spring16 bearing upon the support 11, whereby the proper pressure-contact of29 directly upon the diaphragm 9 is obtained in a manner wellunderstood. The electrode 29 is tubular, or partly so, and arranged tocontain a determined quantity of granulated carbon 21, that makes alight normal contact between the two electrodes, similarly as describedwith reference to section 145. A modification of this form ofconstruction is represented in Fig. 4, in which, in the piece 11, twoopenings are shown, 142 143, containing the electrodes 15 15. In thisform, in section 142, the electrode 15 is supported upon a Hat spring16, secured to piece 11 by means of a screw 17, the electrode 15,preferably of carbon, being provided with one or more cone-shaped pointsthat rest upon or enter into the loose granules 21 underneath the same,the proper pressure-contact between the electrode 15 and the loosegranules of carbon or other material being obtained by means of theadjustable screw 18. In section 142 the electrode 15' is held upon aspiral spring 16', the pressure-contact being obtained by means of thespring 16 and adjusting screw 18 in the cap In Fig. 4 the circuits arefrom the batteries B4 B5, as follows: From B4 wire 34, screw 35, wire36, cap 33, spring 16', electrode 15, granules 21, diaphragm 9, wire 37,back to battery 38 by line or local circuit, and from B5 wire 39, spring16, electrode 15, granules 21, diaphragm 9, wire 37, back to battery asbefore.

In Fig. 5 I have shown a modiiication representing various ways ofproducing a variable contact of the electrodes. In sections 42 43 44 Iemploy metal tubes which contain granulated carbon (shown by small dots)surrounding metal or carbon contacting-pieces, which may be of variousforms of construction. In section 42 a cap or cover 49 is provided, towhich is secured two or more downwardly-projecting pins 52, said cap andpins being free to be rotated, if desired, for the purposes ofadjustment in the particles of carbon surrounding them. In section 43the granules surround a cone or other shaped piece of metal or carbon 54secured to the diaphragm 9, a cap 50 being provided to irmly close thetube to keep the material in place. In section 44 the granulated carbonsurrounds an adjustable screw 53 held in the cap 51. In these forms themetallic contact-pieces serve to increase the surface and preservecontact and also serve to prevent the packing of the loose carbon.

The supporting-piece 11 is held adj ustably to the ring 2 by meansof thescrews 40 40 4l 41 passing therethrough into the ring 2.

The plan or method for utilizing the electric energy and also thecircuit as used will be best understood from the following description,reference being had to Fig. 1, in which, as shown7 the same pole or sideof the eight batteries B to B7 are connected respectively to the insideprimary wires of the eight induction-coils 4, the several outsideprimary wires being connected respectively to the several electrodecarriers 16, thence from the electrodes to diaphragm 9, to ring 2, andby wire D, contact E, spring-key F, wire G to II and connectionstherefrom back to the batteries. The secondary wires of the severalinduction-coils are preferably connected up in parallel, the insidewires to the conductor K and the outside wires to the conductor L, thatare respectively connected to line L or earth E' or to a metalliccircuit M M, which may include any suitable receiving-instrument N.Under this plan the current from the different batteries passes over theprimary of its respective induction-coil and the electrodes in thecircuit therewith, thence back to battery, the induced currents from theseveral induction-coils combining as a whole or acting conjunctively andin unison, whereby the working current is in proportion to the number ofsections of the transmitter employed, thus largely increasing theresults at the receiving apparatus.

It will be understood that a single transmitter may have any number ofsections proportioned to the diameter of the diaphragm and the size ofthe electrodes, and that all of the electrodes are actuated andcontrolled simultaneously and the current carried thereby varied by themovement of a single diaphragm.

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By means of a suitable circuit-closing key, as at E F, included in thebattery-circuit, telegraphing and calling or signaling can beaccomplished by the use of the battery or batteries, thereby dispensingwith the necessity of magnets, bells, or other signaling devices.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

l. A telephone-transmitter characterized by a single diaphragm inelectric contact through the medium of interposed carbon granules, orsimilar material, with and actuating two or more electrodes insulatedfrom and independent of each other, arranged to conduct the current fromtwo or more independent batteries to the Vdiaphragm in electric contacttherewith and the return-circuit to the batteries, substantially asdescribed.

2. In an apparatus for the electrical transmission of articulate speech,the combination of two or more independent batteries connected to theirrespective electrodes, two or more induction-coils having theirprimaries in circuit with two or more independent electrodes insulatedfrom each other, and with independent batteries, and their secondarycoils connected in parallel in another circuit, and a single diaphragmor other vibrator in electric contact with all of the independentelectrodes and actuating the same, substantially as shown and described.

3. An apparatus for transmitting speech having in combination a singlediaphragm, or other vibrator, in electric contact with thereturn-circuit of one or more batteries, and two or more independentelectrodes insulated from each other, in electric contact with theirrespective batteries, and also with the diaphragm or other vibratorthrough the medium of granules of carbon or other similar materialinterposed between the independent electrodes and the diaphragm.

4. In a telephonie transmitter, the combination with a diaphragm, ofmeans for supporting and securing the same under proper tension, one ormore spring-supported electrodes below the diaphragm but not in contacttherewith, a ring or washer of suitable soft material surrounding theend ofthe electrode, granulated carbon or other suitable conductorinterposed in the space between the diaphragm and the electrode, andadjustable means for obtaining the proper pressure-contact between theelectrode granulated material and the diaphragm, as and for the purposeset forth.

` 5. In a telephonie transmitter, the combination with a diaphragm, ofsuitable means for supporting the same,tubular electrode springsupportedand arranged opposite the diaphragm, granulated carbon or other similarconducting material interposed between the diaphragm and the tubularelectrode, and partly contained within the electrode,with adjustablemeans obtainin g the proper pressurecontact between the diaphragm, theelectrode,

and the granulated material, whereby a desired normal contact may beobtained between the diaphragm and the electrodes by pressure andsimultaneously therewith, a light or microphonic contact obtainedbetween the same by means of the loose granules contained within theelectrode, as and for the purpose set forth,

G. In atelephonic transmitter, a diaphragm 9, a hollow or partly hollowor tubular electrode 29, fiat spring 16 provided with lugs 32, 32,adjusting-screws 30, 30, 3l, 31, granulated material 2l, whereby adesired normal contact may be obtained directly between the electrodeand the diaphragm, and simultaneously therewith a microphonic contactbetween the saine by means of the loose granules contained within theelectrode, as and for the purpose set forth.

7. A telephonietransmitter having in combination, a containing box orcase, a diaphragm of ,carbon 9, a diaphragm-holder 2, with means forsecuring the diaphragm, a non-conducting piece l1 sectionally divided,adj ustably supported opposite the diaphragm by the screws 40, 40, 41,4l, and arranged to carry two or more independent battery-electrodes,such as 46, 49, 52, or 48, 5l, 53, or 47, 50, 54, granulated carbon orother suitable material 2l interposed between the independentbattery-electrodes and the diaphragmelectrodes, a sectionally-dividedwasher of felt, cotton-wool, or like material 20, secured to ll, andarranged to rest upon the diaphragm 9 and to hold the loose conductingmaterial in place, all constructed and arranged substantially as hereinshown and described.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES ADAMS RANDALL. Witnesses:

G. A. nn KATON, T. F. BARNES.

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